US President Obama, bowing to heavy pressure from fellow Democrats and a storm of criticism from Republicans, has ordered changes to his healthcare law.

He has agreed to allow the continued sale of insurance plans that have been cancelled for Americans in the private marketplace because they failed to meet coverage standards under the overhaul.

Mr Obama said he had "heard loud and clear" from Americans who are facing cancellation despite Mr Obama's promise that his signature legislation would allow all Americans to keep their current insurance plan if they liked their coverage.

Even so, Mr Obama said he was not going to "walk away from" the law that would help tens of millions of Americans to afford health insurance and that has brought down the cost of healthcare.

"The affordable care act is going to work," Mr Obama said. "We're just going to continue chipping away at this until the job is done.

Mr Obama has been under pressure from congressional Democrats to give ground on the cancellation issue under the healthcare overhaul, a programme likely to be at the centre of next year's mid-term elections for control of the House and Senate.

The decision marks an abrupt switch in position.

The clunky roll-out has given Republicans a new line of attack ahead of the elections, which they hope will offset the drubbing they took in public opinion over last month's 16-day partial government shutdown.